3,319 research outputs found
Symmetry Operators for the Fokker-Plank-Kolmogorov Equation with Nonlocal Quadratic Nonlinearity
The Cauchy problem for the Fokker-Plank-Kolmogorov equation with a nonlocal
nonlinear drift term is reduced to a similar problem for the correspondent
linear equation. The relation between symmetry operators of the linear and
nonlinear Fokker-Plank-Kolmogorov equations is considered. Illustrative
examples of the one-dimensional symmetry operators are presented.Comment: This is a contribution to the Vadim Kuznetsov Memorial Issue on
Integrable Systems and Related Topics, published in SIGMA (Symmetry,
Integrability and Geometry: Methods and Applications) at
http://www.emis.de/journals/SIGMA
Numerical modelling of heat transfer during impact of a molten droplet on a surface
SPH-based numerical technique for modelling of impact of molten drops on a surface with heat transfer and phase transitions effects is proposed. Computational algorithm uses SPH with procedure of restoring of particle consistence and variational approach to calculation of acceleration field. Also, boundary algorithm for free and contact surfaces in 3D setting are develope
ELECTROPNEUMATIC AUTOMATION EDUCATIONAL LABORATORY
The article reflects current situation in education regarding mechatronics learning difficulties. Com-plex of laboratory test benches on electropneumatic automation are considered as a tool in advancing through technical science. Course of laboratory works developed to meet the requirement of efficient and reliable way of practical skills acquisition is regarded the simplest way for students to learn the ba-sics of mechatronics
Possible roles, positions, factors and components of dairying in organic farming – a rewiev, mapping, survey and comparison in the Czech Republic
The full-value experiment is questionable in evaluation organic dairying. It is problem to do a trial under
comparable conditions for comparison of organic and conventional farming because of legislative reasons
and necessity of long period of such event. Most of comparisons are carried out as practice descriptive
observations and any of them has been carried out about milk production. That is main reason, why the aim of
this work is to carry out a opening of monitoring of some production conditions and results of bio-dairying in
the Czech Republic (CR). The quality aspects of sources, procedures and products are main topics of solution
of projects about organic farming philosophy, in particular in solution of organic dairy foodstuff chain. There
were choosen twelve organic dairy farms (survey II, 2006) for more detail research of production conditions
according to results of exploratory questionnaire (2006, survey I, n = 85 pieces of questionnaire and 58
organic farms, which practicise dairying) in the CR. The climatology characteristics of selected organic dairy
farms were as follows: (I) 562±149 m above sea level on the average (from 270 to 970 m a. s. l.); (II)
571.0±69.9 m above sea level, mean year temperature 6.0±1.1 ºC and average year rainfall sum 843.0±184.3
mm. It is clear according to previously mentioned figures that the organic (ecology) dairy farming is realized
mostly in the mountain or sub-mountain areas (less favourable areas, LFAs) as compared to climatic
conditions of CR mean profile.
The results of investigation of organic farm (E) and breeder conditions and dairy cow health state,
reproduction performance and milk quality in organic farms (I data file) as compared to conventional dairy
cow herds (K) were: milk yield (E) was 14.2±3.4 kg of milk/cow/day on average and 5165±1112 kg/cow/year;
E farms have 50 % free stables, some of them as different untraditional modifications (mostly in herds with
low number of dairy cows); it is necessary to increase this amount for welfare improvement in the future;
there are 52 % of binding stables in K herds; there (E) is high occurrence frequency of can milking
equipments (46.4 %); there are 5.4 % cases of hand milking, 21.4 % of pipeline milking equipments and 26.8
% of milking parlours; there (K) are 3 % of can milking equipments, 50 % of pipeline milking equipments
and 47 % of milking parlours; the average organic herd has 60±91 heads it means about 1/3 of K herd in the
CR; geometrical average (xg) of organic herd size is 17 heads; daily milk deliveries were 1318±1475 kg in
summer and 976±1368 kg in winter season (there is too high variability in the mentioned indicators); breed
structure of E herds is 59.8 % of Bohemian Spotted cattle, 18.8 % of Holstein (H), 12.5 % of Jersey breed; H
breed is dominating 47.5 % in K herds; average ratio of excluded milk (for secretion disorders or treatment)
is 2.99 % in E herds and 4.6 % in K herds (P<0.01); also there (E) is lower occurrence of clinical mastitis
0.53±1.97 %; service period is 124.3 days in K and 98.7±46,1 days in E herds on average (P<0.01); there (E)
is better insemination index 1.66±0.45 in comparison to K herds 2.07 (P<0.01); there is longer longevity as
duration of production life of dairy cows in E herds (6.02 lactations, „about 141 % better”) in comparison to
K herds (2.50 lactations, P<0.01); milk quality showed the average total mesophilic bacteria count (CPM)
36.0±26.8 ths. CFU/ml in organic farms (E), which is comparable to the conventional farms (K); somatic cell
count (PSB) was 192±87 ths./ml in E herds and 256 ths./ml in K herds, which is in connection with the lower ratio of milk exclusion from delivery in E herds; an occurrence of residues of inhibitory substances (RIL) was
not reported in E herds, which is more advantageous in comparison to the K herds (0.16 %) and it could be
an impact of lowered antibiotica drug use; the average fat and lactose contents (T; 4.05±0.19 %) and (L;
4.83±0.15 %) are well comparable with K farms and the results show on higher energy deficiency in E herd
nutrition.
The water quality (II) is necessary in dairying as well. Drinking water is necessary for health of animals
(their watering) and for milk quality (milking equipment sanitation) as well. Drinking water is asked in dairy
farms by legislation. The E farm water quality: the nitrate level varied in the range from 1.63 to 28 mg/l with
average 10.5 mg/l in ecological farms and standard limit 50 mg/l was not exceeded; the levels of nitrite and
ammonia ions were mostly under detection limit of method; legislative limit <0.5 mg/l was not exceeded by
nitrite and once by ammonia ions 0.81 mg/l. The microbiological indicators are more sensitive of course. In
total the limits were exceeded 7× u in coliform bacteria, 3× in streptococci and Escherichia coli was
confirmed 3× (in comparison to demand 0). Therefore it is necessary to take care of incidental water source
sanitation.
The effect of origin of water source (communal water pipes or own well in the organic farm area) which
was used in the organic farming (II) was: the more marked result differences were not observed between own
wells (S) and communal water supply (V) in E farms; an exception was stated in insignificantly better results
of hygienic indicators of communal supply; therefore it is necessary to put the higher importance on
sanitation of own water sources. There were identified eight own wells and four communal supply. E. g.
nitrate levels were a little higher for wells 11.7 > 8.2 mg/l. The nitrites were not different. Chemical oxygen
consumption was 0.45 and 0.52 mg/l. The more expressive differences were identified in chlorides, sulphates
and Mg: 8.33 and 3.02 mg/l; 27.9 and 16.8 mg/l; 18.9 and 3.5 mg/l
UniquID: A Quest to Reconcile Identity Access Management and the Internet of Things
The Internet of Things (IoT) has caused a revolutionary paradigm shift in
computer networking. After decades of human-centered routines, where devices
were merely tools that enabled human beings to authenticate themselves and
perform activities, we are now dealing with a device-centered paradigm: the
devices themselves are actors, not just tools for people. Conventional identity
access management (IAM) frameworks were not designed to handle the challenges
of IoT. Trying to use traditional IAM systems to reconcile heterogeneous
devices and complex federations of online services (e.g., IoT sensors and cloud
computing solutions) adds a cumbersome architectural layer that can become hard
to maintain and act as a single point of failure. In this paper, we propose
UniquID, a blockchain-based solution that overcomes the need for centralized
IAM architectures while providing scalability and robustness. We also present
the experimental results of a proof-of-concept UniquID enrolment network, and
we discuss two different use-cases that show the considerable value of a
blockchain-based IAM.Comment: 15 pages, 10 figure
Rotational predissociation of extremely weakly bound atom-molecule complexes produced by Feshbach resonance association
We study the rotational predissociation of atom - molecule complexes with
very small binding energy. Such complexes can be produced by Feshbach resonance
association of ultracold molecules with ultracold atoms. Numerical calculations
of the predissociation lifetimes based on the computation of the energy
dependence of the scattering matrix elements become inaccurate when the binding
energy is smaller than the energy width of the predissociating state. We derive
expressions that represent accurately the predissociation lifetimes in terms of
the real and imaginary parts of the scattering length and effective range for
molecules in an excited rotational state. Our results show that the
predissociation lifetimes are the longest when the binding energy is positive,
i.e. when the predissociating state is just above the excited state threshold.Comment: 17 pages, 5 figure
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